#[cfg(test)]
mod tests {
    #[test]
    fn test_arr() {
        let mut arr = [0; 3];

        arr[1] = 1;
        arr[2] = 2;

        for x in arr.iter() {
            println!("{}", x);
        }

        let mut v = vec![];

        v.push(1);
        v.push(2);
        v.push(3);

        println!("vec iter..");
        for x in v {
            println!("{}", x);
        }

        let mut hello = String::from("Hello");

        hello.push_str(", world");

        assert_eq!("Hello, world", hello);
    }
}
